Hi,
As another solution, it could be useful to have a static page available on the site (in the bookshelf somewhere) that would list all the common conversions, so it can be a handy reference when people are looking for something.
I'm having similar problems with the recipes on the site, the ingredient lists in the books i've been looking at have no quantites listed. This makes the shopping list somewhat less then useful, as I'd get to the shop and not know how much of a ingredident I need. So i'll either under-buy and end up unable to make the recipe, or over-buy and potentially lead to food wastage.
As one of the reasons I signed up here was to take advantage of being able to check my cookbooks from the store/market when goods are on special or of good quality. Its somewhat disappointing.